Towards Realistic High-Speed Train Channels at 5G Millimeter-Wave Band—Part II: Case Study for Paradigm Implementation

In this paper, we present two case studies for generating realistic high-speed train (HST) channels at fifth-generation (5G) millimeter-wave (mmWave) band. The first one is the tunnel environment at relatively low 5G mmWave band, 30 GHz band, whereas the second one is the outdoor HST environment at relatively high 5G mmWave band, 90 GHz band. Both case studies include the following steps: ray-tracing simulations, stochastic channel modeling and realization, verification with ray-tracing simulations, and validation with a reduced set of measurements. A profound and insightful conclusion is reached that by employing the proposed paradigm, realistic channels can be realized for the design and evaluation of 5G mmWave communication systems in high-speed railways, even without the support of sufficient channel sounding data.